linux-kernel - Re: Bug: wild-memory-access in get_cpu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20241224121442.GBZ2qlsvTsih56XhJo@fat_crate.local>
Date: Tue, 24 Dec 2024 13:14:42 +0100
From: Borislav Petkov <bp@...en8.de>
To: Kun Hu <huk23@...udan.edu.cn>
Cc: tglx@...utronix.de, mingo@...hat.com, dave.hansen@...ux.intel.com,
	x86@...nel.org, hpa@...or.com, jpoimboe@...nel.org, xin@...or.com,
	pawan.kumar.gupta@...ux.intel.com, tony.luck@...el.com,
	andriy.shevchenko@...ux.intel.com, linux-kernel@...r.kernel.org,
	"jjtan24@...udan.edu.cn" <jjtan24@...udan.edu.cn>
Subject: Re: Bug: wild-memory-access in get_cpu_cap

On Tue, Dec 24, 2024 at 07:48:09PM +0800, Kun Hu wrote:
> 21: b8 06 00 00 00 mov $0x6,%eax
> 26: 31 c9 xor %ecx,%ecx
> 28: 0f a2 cpuid
> * 2a: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx <-- trapping instruction

A non-canonical memory access, most likely some gunk KASAN does.

It should go away when you disable KASAN. You could debug further to
figure out why KASAN is even doing this...

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette